Automatic air gauge



VMay 17, 1949. A, C, HALLMARK 2,470,164

AUTOMATIC AIR GAUGE Filed Dec. 18, 1947 Aubrey C H a//mark JNVENTOR.

Y @zum adyowmw Patented May 17, 1949 UNITED STATES PATENT OFFICE AUTOMATIC AIR GAUGE Aubrey C. Hallmark, Naval Base, S. C. vApplication December 18, 1947, Serial No. '792,485

6 Claims. (Cl. 137-695) This invention relates generally to gauges, more particularly to an automatic shut oif air gauge adapted to limit the pressure on the outlet side of the gauge to a predetermined setting of the gauge.

The primary object of this invention is to pro- \vide a gauge which is particularly well adapted for use in inflating tires of automotive vehicles, and kindred devices necessitating a reasonably accurate limitation of the pressure applied to the devices.

Another object of this invention is to provide `a device of this character in which the shutting lwhich has no projecting parts and is therefore very safe to use, and which can be made very light in weight so that the device may be conveniently secured on the end `of an air hose.

And the last object to be particularly mentioned is to provide an automatic shut oi air gauge which is relatively inexpensive and prac ticable to manufacture, which is very convenient and simple to operate, and which will give generally efcient and durable service.

With these objects definitely in view, together with other objects of a specific nature which will appear hereinafter as this description proceeds, this invention resides in certain novel and improved arrangement, combination and construction of elements and portions which will be hereinafter described in the specification, particularly pointed out in the appended claims, and illustrated in the accompanying drawings which form a material part of this application, and in which:

Figure 1 is a side elevational View of the assembled gauge;

Figure 2 is a longitudinal vertical sectional view Iof the gauge, taken substantially along the longitudinal center line of the gauge; and

Figure 3 is a transverse vertical sectional view of the gauge, taken on the line 3-3 of Figure 1 and in the direction of the arrows.

Similar characters of reference designate similar or identical elements and portions throughout the specification and throughout the several views of the drawings.

Referring now to the drawings in detail, this ses invention includes a body represented as being of elongated form and generally indicated by the numeral I0. The body is longitudinally bored at I2 and a nipple I4 is threadedly secured to one end of the body in communication with the bore I2, this nipple being adapted to receive an end of an air hose of conventional design. The other end of the bore I2 is illustrated as inclined at an angle less than degrees and this inclined portion I6 of the bore communicates with the chamber I8, a throat portion of the inclined bore I6 being internally threaded to receive the threaded securing collar 20 of a check valve which will ordinarily be of the type commonly termed a valve core as used in many types of pneumatic equipment. The remaining portions of this core 22 are disposed within the inclined bore I6, which must, therefore, ibe of a suiiicient length to accommodate the same. The core plunger 24 extends into the chamber I8. A neck portion 26 of the body I0, adjacent the chamber I8, is disposed in substantially the same direction as the inclined bore I6 and this neck portion is in teriorly threaded to receive internally an externally threaded sleeve 28 and an externally threaded bushing 3l), the latter having an internal diameter sufficiently large-` to receive the end of a conventional valve stem in sliding relation. A washer 32 of rubber or of similar resilient material is inserted between the sleeve 23 and the bushing 30 and this washer is centrally apertured to receive a valve actuating pin 34 carried by the outlet valve 36, a plunger portion 38 of which is guided by the internal sleeve 28, while a spring 40 is compressed Within a bore 42 and between the ends of this bore and the end of the outlet valve stem, all as clearly indicated in. Figure 2. It should be carefully noted that the plunger portions 24 and 38 of the two valves are mounted to move in substantially the same direction.

The casing I0 is also provided with a bore 44 communicating with the chamber I8 and closed iby a screw plug 46. A piston 48 having a sealing washer 50 secured on one end thereof by a headed stud- 52, is reciprocatively mounted within the bore 44. This piston is hollow and carries an irregularly shaped member 54 which is inserted vthrough a centrally apertured plug 56 vertically secured in the open end of the piston 4B disposed toward the chamber I8. The member 5i is provided with an enlarged head 5B adapted to abut the plug 56 and a spring 59 is compressed between this head i58 and the head of the piston. It will be carefully noted that the end 5I! of the member 54 projects slightly beyond the inner edge of the sleeve 28 so as to engage the plunger 38 when the piston 48 is in position illustrated in Figure 2 and when the spring 58 is fully extended.

An elongated recess 62 is provi-ded in the body Il) between the bores I2 and 44, this recess opening on one side of the body I0. An elongated lever 64 has a laterally extending arm 56 at one end thereof adjacent the piston 48; and it is preferred that the wall 68 between the bore 44 and the recess S2 should be apertured, as indicated at 10, to allow this laterally extending arm 66 to.;

extend into the bore 44 so that a knife edge 'l2 on the outer extremity of the arm 66 vmay contact the head of the stud 52, whilethe portionF of the wall 68 surrounding the aperture In comprises a fulcrum for the lever-64;-

The recess B2 has been described as openonone side of the body i0, and this opening is closed by a plate 14 which may be secured to the body by screws 1B, while the inner side of the plate 'I4 carries a pair of plate members 18' having portions 80- disposedl toward the center of the plate 'I4 offset inwardly to receive anend-f less strap 82, that is, thatportion of the endless strap disposed toward the plate 14, it being understood thatthis iiexible strap comprises a loop of a length corresponding generally with the length ofthe recess B2.` A finger grip 84- is mounted for longitudinal sliding movement on the plate 14, this plate having a longitudinally disposed slot 86 which receives an arm 88 carried by the nger grip 84' and terminating at its inner end in a block 90 which is thus made freely slidably adjustable longitudinally of the recess 62'; This block 90 carries a flat spring 92, the free end of which contacts the sideof the lever 64 remote from theV bore 44. Indicia 94 will be placed on the plate 14 so as to constitute a scale of pressures obtainable by the use of this gauge, the scale being read, of course, with reference to an edge of or indicia on the nger grip 84.

The operation of this invention Iwill be clearly understood from theforegoing description of the mechanical details thereof, taken in connection with the above recit-ationl of the objects thus to be achieved by this invention. In recapitulation, it may be noted that movement of the nger grip 84 will shi-ft the spring 92 along lthe lever 64. Obviously this shifting of the spring S2 will cause a variation in the pressure required to move the piston 48. When-a valve stem of the article to be inated is inserted into the bushing 30, the valve plunger in this valve-stem will contactthe actuating pin 34 and push this actuating pin inwardly so that the plunger 38 moves the end 5i) of the member 54 into contact with the plunger 24, and pressurized air will be admitted into the chamber I8 and into the article being inflated. However, when the pressure is increased suiiiciently within the chamber I8 to move the piston 48, that is, to' actuate the lever 64 against the action of the spring 92 4as positioned by the nger grip 84, then the end Sll'of the member 54 will be moved from its position between the plungers 24 and 38. The plunger 24 will snap back into position closing the inlet valve, and upon removal of the gauge from the valve stem of the article beingl inflated, the pressure in the chamber I8 will drop to that of the atmosphere and the spring 40 will urge the valve 36 back into the positionl represented in Figure 2. It should be carefully noted' that the spring 58`is considerably weaker than the spring 40; so that the valve 36 will not be prevented from closinvention, what is anelongated body having an air inlet channel and a chamber therein, an inlet valve controlling Vnow` between said channel and chamber, an outlet valve for said chamber and having means whereby it can be opened by externally applied force, a member providing in one position mechanical contact between said valves vso that opening of the outletvalve causes the inlet valve toA open, shiftable vmeans responsive to pressure within saidchamber and connected to said'mem-zber for moving said member o ut of said one p0 sition when a predetermined pressure in the chamber is attained, and variable biasing means operatively connected withv said `shif'table means;

2. An automatic shutoff air gauge comprising an' elongated bodyA havinganf-air inlet channel and a chamber therein, an inlet valve controlling iiow between said channel' andv chamber, anoutlet valve for said chamber and having means whereby it can be opened by externallyA applied-force, a member providingy inV one position mechanical contact between said `valves so that openingvovf the outlet valve causes the inlet valve to open, shiftable means responsive to pressure-Within said chamber and connected to saidmember for moving said member out of said one' position when a' predetermined pressure inv thecham-ber is attained, and variable biasing means opera tively connected withl saidl shiftable means, said valves each having plungers operating in substantially the same' direction, and said` member being disposed between adjacent portions of said plungers when in said one position.

3. An automatic shut-off air gauge comprising an elongated body having anair inlet channel and a chamber therein, an in let valve controlling ow between said channel and chamber, an outlet valve for said `chamber andhaving means whereby it can be opened by externally appliedV force; a member providing in one position mechanical contact between saidV valves so tha-t'opening-of the outlet valve causes the inletvvalve to open, shiftable means responsive to pressure within said chamber andfconnected to said member formaving said member out of=said one position when a predetermined pressure in' the chamber isat.'- tained, and variable biasingl means operatively connected with said shiftablemeans, saidv body having a cylinder communicating with said chamber, said shiftable means comprising a pistonin ,said cylinder, .and said member being Vcarried by said piston.

4- An automatic shut ofi air gauge Comprising an elongated body having an air inlet channel and a chamber therein; aninlet valve controlling flow between said channel and chamber, an 'outlet valve for said chamber and'havingmeans'whereby it can be opened by externally Aapplied force,v a. member providing` in' oneY position mechanical contact between saidvalvesI so'tliat opening of the outlet valve causes the inletl valve' toppen,

shiftable means responsive to pressure within said chamber and connected to said member for moving said member out of said one position when a predetermined pressure in the chamber is attained, and variable biasing means operatively connected with said shiftable means, said biasing means including a lever operatively connected with said shiftable means, and a, spring longitudinally adjustable on said lever to bias the lever in one direction to move said shiftable means so that said member is moved into said one position.

5. A gauge according to claim 4 and in which said spring has a carrier slidably mounted on the body, said carrier having an arm terminating in a fin-ger grip extending exteriorly of the body for manual adjustment of the spring along said lever.

6. A gauge according to claim 5 and in which said body has an elongated recess to house said spring and lever and having an opening on side REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 15 1,495,553 Durham May 27, 1924 1,765,850 IRichardson June 24, 1930 1,768,275 Urton June 24, 1930 

